youden: Youden Statistic

In spatstat.explore: Exploratory Data Analysis for the 'spatstat' Family

Youden Statistic

Description

Calculate the Youden statistic for an ROC curve.

Usage

youden(X, sign = c("positive", "absolute", "negative"))

Arguments

X	ROC curve (object of class "roc" produced by roc).
sign	Character string indicating which version of the statistic to calculate.

Details

For a receiver operating characteristic (ROC) curve, the Youden statistic is the maximum vertical deviation between the curve and the diagonal line y=x.

Suppose R(p) denotes the ROC curve as a function of the horizontal coordinate p. If sign="positive" (the default), deviation is defined as the positive part \max(0, R(p)-p). If sign="absolute", deviation is defined as the absolute value | R(p) - p|. If sign="negative", deviation is defined as the negative part \max(0, p - R(p)). The maximum deviation over all values of p is determined. The result is always nonnegative.

Value

Numeric value or vector, containing nonnegative values.

Author(s)

\adrian

.

References

Youden, W.J. (1950) Index for rating diagnostic tests. Cancer 3, 32–35.

See Also

roc, auc

Examples

  a <- with(split(mucosa), roc(ECL, "y", baseline=other, high=FALSE))
  youden(a)

spatstat.explore documentation built on Aug. 8, 2025, 7:36 p.m.